Merge PMArbitraryPrecisionFloatForTrigonometry with PMArbitraryPrecisionFloat

[SergeStinckwich]

@nicolas-cellier-aka-nice why do we need a separate class only for sin, cos and pi for arbitrary precision floatPMArbitraryPrecisionFloatForTrigonometry? I think we can merge with PMArbitraryPrecisionFloat to avoid confusion.

[nicolas-cellier-aka-nice]

Yes, good idea, the only thing to care of is the precision of pi used in the subclass.

[SergeStinckwich]

Do you mind to do a PR with this modification? Thank you.

[nicolas-cellier-aka-nice]

I've implemented upstream, see issue #199

[SergeStinckwich]

ok thank you. I have to see how to see the changes between the upstream and the PM version.